Use of morselized allografts for acetabular reconstruction during THA revision: French multicenter study of 508 cases with 8 years' average follow-up.

BACKGROUND: In the context of acetabular reconstruction, bone defects can be filled with processed or unprocessed bone allografts. Published data are often contradictory on this topic and few studies have been done comparing processed allografts to fresh-frozen ones. This led us to conduct a large study to measure the factors impacting the survival of THA revision: (1) type of allograft and cup, (2) technical factors or patient-related factors. HYPOTHESIS: Acetabular reconstruction can be performed equally well with frozen or processed morselized allografts. MATERIALS AND METHODS: This retrospective, multicenter study of acetabular reconstruction included 508 cases with a minimum follow-up of 5 years. The follow-up for the frozen grafts was shorter (7.86 years±1.89 [5-12.32]) than that of the processed grafts (8.22 years±1.77 [5.05-15.48]) (p=0.029). However, the patients were younger at the time of the primary THA procedure in the frozen allograft group (51.5 years±14.2 [17-80]) than in the processed group (57.5 years±13.0 [12-94]) (p<0.001) and were also younger at the time of THA revision (67.8 years±12.2 [36.9-89.3] versus 70 years±11.7 [25-94.5]) (p=0.041). RESULTS: There were more complications overall in the frozen allograft group (46/242=19.0%) than the processed allograft group (35/256=13.2%) (p=0.044) with more instances of loosening in the frozen group (20/242 [8.2%]) than in the processed group (6/266 [3.3%])(p=0.001). Conversely, the dislocation rate (16/242=6.6% vs. 17/266=6.4%) (p=0.844) and infection rate (18/242=7.4% vs. 15/266=5.7%) (p=0.264) did not differ between groups. The subgroup analysis reveal a correlation between the occurrence of a complication and higher body mass index (BMI) (p=0.037) with a higher overall risk of complications in patients with a BMI above 30 or under 20 (p=0.006) and a relative risk of 1.95 (95% CI: 1.26-2.93). Being overweight was associated with a higher risk of dislocation (relative risk of 2.46; 95% CI: 1.23-4.70) (p=0.007). Loosening was more likely to occur in younger patients at the time of the procedure (relative risk of 2.77; 95% CI: 1.52-6.51) (p=0.040) before 60 years during the revision. Lastly, patients who were less active preoperatively based on the Devane scale had an increased risk of dislocation (relative risk of 2.51; 95% CI: 1.26-8.26) (p=0.022). DISCUSSION: Our hypothesis was not confirmed. The groups were not comparable initially, which may explain the differences found since the larger number of loosening cases in the frozen allograft group can be attributed to group heterogeneity. Nevertheless, morselized allografts appear to be suitable for acetabular bone defect reconstruction. A randomized study would be needed to determine whether frozen or processed allografts are superior. LEVEL OF EVIDENCE: III, comparative retrospective study.

Gait analysis following medial opening-wedge high tibial osteotomy.

PURPOSE: High tibial osteotomy (HTO) is used to treat young and active patients with knee osteoarthritis (OA) and varus deformity. The medial compartment OA alters the patients' gait. METHODS: A prospective study was carried out in 21 consecutive patients operated for HTO due to knee OA with varus deformity. There were 14 men and 7 women, with a median age of 51.9 years (38-64). Their gait was analyzed preoperatively and at 1 year postoperatively, and compared to a healthy control group. Clinical assessment (KOOS, WOMAC, Lysholm, and SF-36 scores) was also performed preoperatively and postoperatively. RESULTS: Patients with medial compartment OA had altered gait relative to the control population. Their walking speed was slower, step length was shorter, and single-leg stance time was shorter, while the double-leg stance time was longer (P < 0.001). Step width was not different between the two groups preoperatively (n.s.), but it was wider in the patient group postoperatively (P = 0.003). There were no differences in the patients' gait parameters before and after the osteotomy (n.s.). However, there was an improved perception of walking so that it is no longer different from controls (n.s.). The KOOS, WOMAC, Lysholm and SF-36 scores improved after HTO. The preoperative median of 7° varus (1-11) was corrected to 3° valgus (0-6). CONCLUSION: Medial compartment OA with varus deformity leads to gait modifications. HTO does not alter the time-distance parameters of gait; however, patients have improved perception of their walking ability. HTO leads to excellent results for knee function, and improves quality of life without modifying the gait pattern. LEVEL OF EVIDENCE: II.

Moore I postero-medial articular tibial fracture in alpine skiers: Surgical management and return to sports activity.

PURPOSE: Over the past 10 years, like many authors, we observed an increasing number of Moore I tibial plateau fractures related to alpine skiing for which the surgeon may face difficult choices regarding surgical approach and fixation means. Some authors have recently been suggesting a posterior approach associated to open reduction and osteosynthesis by a buttress plate. But in our knowledge there is no specific study on sports activity recovery after Moore I tibial fractures. The aim of this work was to assess sports activities and clinical outcomes after surgically treated Moore I tibial plateau fractures in an athletic population of skiers. METHODS: We conducted a prospective case series between 2012 and 2014. This included fifteen patients aged 39.6±7 years whom presented with a Moore I tibial plateau fracture during a skiing accident. 12 cases (80%) presented with an associated tibial spine fracture. Treatment consisted of a standard antero-medial approach, with a medial para patellar arthrotomy to allow direct visualisation of articular reduction and spinal fixation. Two or three 6.5mm long cancellous bone screws were placed antero-posteriorly so as to ensure perfect compression of the fracture site. Radiological and functional results were assessed by an independent observer (Lysholm-Tegner, UCLA, KOOS scores) at the longest follow-up. RESULTS: Mean follow-up was 18.2±6 months (12-28). An immediate postoperative anatomical reduction was achieved in all cases and remained stable in time. At last follow-up Lysholm mean score was 85±14 points (59-100), UCLA score was 7.3±1.6 (4-10) and Tegner score was 4.6±1.3 (3-6). Mean KOOS score was 77±15 (54-97). 87% of patients had resumed their skiing activity and 93% were satisfied or very satisfied from their post-operative surgical outcome. We observed no pseudarthrosis or secondary varus displacement. CONCLUSION: In our series 87% of patients had resumed back to their sporting activities. Surgical management of Moore I tibial plateau fractures by isolated antero-posterior screwing provides excellent clinical and radiological results. The anteromedial incision has a dual advantage of anatomical reduction, tibial spine fixation (in 80% of our cases) and posteromedial fragment reduction.

Computer-assisted total knee replacement after medial opening wedge high tibial osteotomy: medium-term results in a series of ninety cases.

PURPOSE: The aim of this study was to evaluate the medium-term results of total knee replacements (TKRs) after medial opening wedge valgising tibial osteotomy to those of primary TKR (TKR1). The hypothesis being that there would be no difference in results between these groups. METHODS: Series 1 was made up of 45 TKRs after medial opening wedge high tibial osteotomy (MHTO)-30 men and ten women at an average age of 69 ± seven years (54-82). This was compared to a second series of TKR1s-30 men and ten women at an average age of 69 ± seven years (55-78). The average IKS scores were 91 ± 22.5 points (42-129) and 86 ± 18 points (38-116) in the two groups respectively. The average pre-operative HKA angle was 179 ± 5° (169-193°) in group 1, and 173 ± 7.5° (161-193°) in group 2. Tibial mechanical axes were 90.5 ± 4° (of which 24 knees had a valgus angle) and 85.05 ± 3.5° (79-93°) in the two groups respectively. RESULTS: All patients were reviewed at an average follow-up of 47 ± 24.5 months for series 1 and 185 ± 8.5 months for series 2. The average IKS score was 184 ± 6 for series 1 (172-200) and 185 ± 8.5 (163-200) for series 2 (p = 0.872). Thirty-seven patients in series 1 and 38 patients in series 2 were either extremely satisfied or satisfied with the intervention. The average post-operative HKA angle was 180.5 ± 2.5° and 181 ± 2° (p = 0.122) and the average tibial mechanical axis was 89 ± 1.5° against 90 ± 1° (p = 0.001). The results of the 24 knees with a valgus tibial mechanical axis were statistically no different. CONCLUSIONS: TKRs post medial opening wedge high tibial osteotomy have identical results to primary TKRs even in knees with a valgus tibial mechanical axis.

Computer navigation for revision of unicompartmental knee replacements to total knee replacements: the results of a case-control study of forty six knees comparing computer navigated and conventional surgery.

PURPOSE: The revision of unicompartmental knee replacements (UKRs) to total knee replacements (TKRs) using computer navigation is a little-known technique. The principal objective of this study was to analyse the radiological position of implants in revision of UKR to TKR comparing the results of surgery aided by computer navigation (CAS) with conventional surgery (CS). Our hypothesis was that computer navigation would improve the position of the implants. METHODS: This is a retrospective single surgeon series. Forty-six patients (46 knees) with an average age 73 ± eight years (53-93) between January 1995 and December 2014 were included. The two groups were made up of 23 patients each and are comparable in terms of age, sex, side of surgery, age of the UKR, cause of failure and HKA angle before surgery. All patients were reviewed by two independent observers. RESULTS: In the CAS group, the average hip-knee-ankle (HKA) angle was 179.2 ± 2.2° (175-184°). The average medial tibial mechanical angle (TMA) was 88.4 ± 1.6° (84-90°) and the medial femoral mechanical angle (FMA) was 91 ± 2° (87- 94°). The tibial slope was 88.7 ± 1.1° (87-90°). In the CS group, the average HKA angle was 179.9 ± 1.9° (175-183°), the TMA was on average 89.1 ± 1.3° (87-93°) and the FMA was 90.6 ± 1.5° (87-93°). The tibial slope was 87.8 ± 4.9° (85-95°). There was no statistically significant difference between the two groups on any of the radiological parameters studied. CONCLUSIONS: Our radiological target of a post-operative HKA angle of 180 ± 3° was obtained in 87.5% of cases in the CS group and 92.4% of cases in the CAS group. This slight difference in favour of the computer-assisted group was not statistically significant, and we cannot therefore confirm our initial hypothesis, at least in the hands of an experienced surgeon. However, the quality of the results in the CAS group suggest that this technique could provide precious assistance to less experienced surgeons performing this surgery.

Desmoplastic fibroma of the ilium.

INTRODUCTION: The desmoplastic fibroma is a rare locally invasive bone tumour. Surgical resection with minimal margins is recommended. PRESENTATION OF CASE: A 15 year-old boy was referred with chronic left thigh pain. MRI revealed a bone lesion within the cavity of the inner table of the left iliac wing without invasion of the underlying bone marrow. A surgical biopsy revealed a desmoplastic bone fibroma. A partial resection of the inner table of the iliac wing sparing the outer table was performed. At the latest follow-up the initially spared iliac wing had needed further resection. The reason proposed for this is devascularisation by substantial periosteal stripping causing partial resorption initially, then necrosis and ultimately ulceration through the skin necessitating further surgical resection. DISCUSSION: The technique of resection of a pelvic desmoplastic fibroma sparing the outer table of the iliac wing has not previously been reported. The objective of a limited resection was to minimize the risk of a postsurgical limp caused by weakness of the gluteus medius muscle. However we report that this technique did not work in this case. A wider resection of the iliac wing as it is recommended for a malignant tumour would have yielded a similar final outcome. CONCLUSION: A partial resection of the iliac wing seemed an appealing technique for a benign tumour of the inner table of the iliac wing. However, considering the complications encountered, the authors advise a simple "en bloc" resection of the iliac wing for this type of tumour in this location.